Under a searing sun the opening phase of the final opportunity to test ahead of next week's Bahrain Grand Prix was dominated by longer runs, with Perez moving up the order courtesy of a 1m31.714s on Pirelli's mid-range C3 tyres.
Mercedes' Hamilton joined the fray with a 1m31.960s on the same compound during what seemed like a more positive afternoon for Mercedes than Friday.
As the sun set, the track became more representative for next week's qualifying and race.
The cooler afternoon conditions therefore prompted more performance runs on Pirelli's softer compounds, with several drivers going quicker than the previous benchmark.
After Carlos Sainz got close to team-mate Leclerc's morning benchmark, Hamilton went top on the softest C5 compound with a 1m30.781s, easily Mercedes' fastest time so far.
That time proved no match for Perez' 1m30.616s on the slower C4 tyres, with Hamilton then improving but still 0.048s behind the Mexican on his next attempt.
In the final hour, with the track continuously getting quicker, Perez put more distance between himself and the seven-time world champion, a 1m30.305s on C4s increasing his lead to 0.359s.
Valtteri Bottas impressed by going third with a 1m30.827s, staying just half a second off Perez in his Alfa Romeo as he jumped both Ferrari drivers.
Behind Leclerc and Sainz, AlphaTauri's Yuki Tsunoda was sixth with his C4 time, narrowly ahead of fellow afternoon runner Kevin Magnussen in the Haas and George Russell's morning time in the Mercedes.
Fernando Alonso took over from Aston Martin's reserve driver Felipe Drugovich as the tandem completed the top 10 on what has been an impressive long run showing by the Silverstone squad.
it proved another low-key day for McLaren as Lando Norris completed just 35 laps to stay 11th, although the Briton set his fastest time on the slower C3 tyres.
Pierre Gasly was 13th in what looked like a tricky new Alpine machine, ahead of Williams marathon man Alex Albon who along with Perez covered the entire Saturday as both drivers hit 130 laps or more.
Morning runners Esteban Ocon, Nico Hulkenberg, Oscar Piastri and Nyck de Vries propped up the timesheets with times in hot conditions that cannot be compared to the faster evening running.
As was the case in every session, a late virtual safety car and red flag for systems checks and a practice start brought an otherwise uneventful session to a close.
With the only three-day winter test completed, teams will now get five days to prepare for Friday's first on-track running of the 2023 curtain raiser at the same Bahrain International Circuit.
2023 F1 Bahrain test: Day 3 results
| Cla | Driver | Chassis | Engine | Laps | Time | Gap |
|---|---|---|---|---|---|---|
| 1 |  Sergio Perez |
Red Bull | Red Bull | 133 | 1'30.305 | |
| 2 |  Lewis Hamilton |
Mercedes | Mercedes | 65 | 1'30.664 | 0.359 |
| 3 |  Valtteri Bottas |
Alfa Romeo | Ferrari | 131 | 1'30.827 | 0.522 |
| 4 |  Charles Leclerc |
Ferrari | Ferrari | 67 | 1'31.024 | 0.719 |
| 5 |  Carlos Sainz |
Ferrari | Ferrari | 76 | 1'31.036 | 0.731 |
| 6 |  Yuki Tsunoda |
AlphaTauri | Red Bull | 79 | 1'31.261 | 0.956 |
| 7 |  Kevin Magnussen |
Haas | Ferrari | 95 | 1'31.381 | 1.076 |
| 8 | George Russell |
Mercedes | Mercedes | 83 | 1'31.442 | 1.137 |
| 9 | Fernando Alonso |
Aston Martin | Mercedes | 80 | 1'31.450 | 1.145 |
| 10 |  Felipe Drugovich |
Aston Martin | Mercedes | 77 | 1'32.075 | 1.770 |
| 11 | Lando Norris |
McLaren | Mercedes | 37 | 1'32.160 | 1.855 |
| 12 |  Pierre Gasly |
Alpine | Renault | 56 | 1'32.762 | 2.457 |
| 13 |  Alex Albon |
Williams | Mercedes | 136 | 1'32.793 | 2.488 |
| 14 | Esteban Ocon |
Alpine | Renault | 76 | 1'33.257 | 2.952 |
| 15 |  Nico Hulkenberg |
Haas | Ferrari | 77 | 1'33.329 | 3.024 |
| 16 |  Oscar Piastri |
McLaren | Mercedes | 44 | 1'33.655 | 3.350 |
| 17 |  Nyck de Vries |
AlphaTauri | Red Bull | 87 | 1'38.244 | 7.939 |
